How do I fix OneNote not allowing me to move or delete a page in a section group?

Check if your section name is longer than 31 characters.
If it is, rename it to a shorter one.
Check if you have any hidden page numbers in the section.
If you do, use the arrow keys to show them before you can delete or move the page.
Check if the section is protected.
If it is, turn off the protection before deleting or moving the page.
Check if there’s multiple levels of section groups.
If so, delete the page from the subsection before deleting it from the section group.
Check if you have a backup of the section.
If you are still having trouble deleting or moving the page, you can easily restore it from the backup.